Zinc Oxide

[Loolee]

My niece has requested a facial lotion with sunscreen. I have zinc oxide ordered. So what is the usage rate so that its effective, but not be like bullfrog where it makes one look like a ghost. is this even possible?

The herbaire says its usage is 1%-15%, but that what they sell isn't used for sunscreen (zinc oxide USP). I ordered mine from Camden Grey and they don't list a usage rate.

TIA!

 

[Relle]

I think the best idea is to contact Camden Grey and ask them the usage rate to be sure.

 

[Evik]

Hi Loolee,

I have some personal experience using ZnO alone in a home-made sunscreen cream. I used it at 30% and must say I got burned a bit on part of arm that was exposed to sun the majority of the day (we hiked, it was in the mountains). I did not use any special oils with higher SPF (like avelane oil for example, see [FONT=Arial, Helvetica, sans-serif]http://www.actahort.org/books/845/845_97.htm[/FONT]), only a carrot seed oil which is full of carotens.
Your cream should have loads of antioxydants, including carotens,vitamin E etc. Also if you make it repairing by adding oils high in phytosterols - such as avocado, that will help. I think Ti2O is very important to be added as well, as it has slightly different wavelength activity and complements the UV protective effect of ZnO.

I found some interesting information on formulations here: http://www.koboproductsinc.com/Downloads/Formulating_natural_sunscreen-March2009.pdf

They show some recipes and the ZnO or Ti2O ingredient percentage. You will see, that majority is over 20%. I would not go below! Also, if you want to be protected, the cream will definitely cover your skin white to some extent- that is the principle of the protection, it is physical...
If you don't like it, you can add some beige teint to it..

Also - the quality and type of ZnO and Ti2O is important. The effectsare different if you use micro or nano-particle, the latter seems to have better effect and is less visible upon the same concentrations. However, there is a lot of buzz around nano-particles and their toxicity, so far the toxic efect in vivo was not proven. One of the latest reviews (http://www.ncbi.nlm.nih.gov/pubmed/22466067) states that

Overall, the weight of scientific evidence suggests that insoluble NP used in sunscreens pose no or negligible risk to human health, but offer large health benefits, such as the protection of human skin against UV-induced skin ageing and cancer.

Hope this helps a bit,

Evik

 

[new12soap]

I have read that zinc oxide and titanium dioxide can be hard to hold in suspension in a lotion, they want to sink to the bottom. That is one of the reasons it can be difficult to get a reliable product.

 

[mel z]

Don't know if this will help or is what you are looking for, scroll down for the recipe:

http://swiftcraftymonkey.blogspot.com/2009/12/zinc-oxide-cream.html

 

[Evik]

I have read that zinc oxide and titanium dioxide can be hard to hold in suspension in a lotion, they want to sink to the bottom. That is one of the reasons it can be difficult to get a reliable product.

Never happened to me. I tried both to mix them with the water phase or once the cream was made.